the original image

... and now pure HTML

we rendered 120 * 67 (8040) pixels into 1465 cells

Optimizations

longest line

Instead of drawing each pixel as a cell (either a DIV or a TD tag) we try to group pixels with the same colour into
one cell. In the first run we try to get the longest row with same colour and then try to expand
it the next rows building a rectangle.
(show the cells) [scaled 4 times]

Square

A second version tries to build squares as a square should have the best size-to-area ratio.
(show the cells) [scaled 4 times]

tranparency

In the div-mode we can drop all the DIVs which have a transparent colour.

Implications

A nice side-effect of using HTML to draw images:

you can scale them for free.

gzip compresses HTML very well (the page here is 6kb for TD, 11kb for DIV)